The invention relates to hydraulic processing grippers or hydraulic processing pincers.
“Processing gripper”, according to the invention, generally refers to a device with which workpieces can be gripped, machined or processed hydraulically and, therefore, with a high application of force. The processing gripper comprises at least two elements that can move in relation to each other and form a working gap between them, one of the elements is a hydraulically actuated press ram and the other element forms a workpiece assembly or a further workpiece element.
A generic hydraulic processing gripper is known in the art from DE 103 59 879 and is used to provide functional elements or connecting elements, such as nuts, bolts etc. in workpieces made of sheet metal by means of joining and subsequent pressing.
Especially for pressing there is a press ram or plunger, which for closing of the processing gripper during feeding can be moved from a press ram or plunger starting position into a working position, in which the plunger is supported on the functional element to be inserted into the workpiece and the functional element is supported on the workpiece. A hydraulic pressure cylinder then fixes the functional element in the workpiece by means of pressing, i.e. by means of permanent material deformation for example of the functional element and/or of the workpiece.
The basic advantage of the known setting gripper is that the feed movement of the press ram or plunger can be executed with a large stroke, and with reduced force, while the increased force required for processing or pressing when the processing gripper is closed is generated by the pressure cylinder, with an extremely short stroke. In order to achieve this, the processing gripper is designed so that the pressure piston of the pressure cylinder is arranged on the same axis with the press ram or plunger. As a result, the plunger, when advanced, is at an axial distance from the pressure piston of the pressure cylinder. Via a pressure element, which can be moved radially to the axis of the press ram, the distance between the pressure piston of the pressure cylinder and the advanced press ram is bridged. The pressure piston then acts on the press ram via this pressure element during pressing. When the press ram is retracted into starting position with the processing gripper open, the pressure element is located to the side of the press ram and therefore provides the free space necessary for the press ram to return to its starting position.
The disadvantage of the known processing gripper is its relatively large overall height, which is due in particular to the fact that the size of the pressure transfer element or pressure element in the axis direction of the workpiece is at least equal to the stroke of this press ram from its starting position to the working position.
It is an object of the invention to present a processing gripper that enables a more compact design while retaining the basic advantages of the existing gripper. This object is achieved by a processing gripper made up of a tool having an axially displaceable tool plunger, which, with a first end and an opposite work rest, forms a working region or a working gap and can be moved with the first end towards and away from the work rest. The processing gripper has a hydraulic actuating device for applying a force to the tool plunger via a movable pressure-transmitting element, the force moving the tool plunger in the direction of the work rest.